Delayed effect of QUIN-neurotoxicity. Ultrastructural study.

The ultrastructural studies of QUIN-injected rat hippocampus were performed in long-term experiment in order to determine delayed neurotoxic effect of this compound. QUIN, in a single dose, was administered stereotaxically into the dorsal hippocampus. The morphological changes were characterized by marked atrophy of neuropil accompanied by remarkable glial pathology. The neuronal changes consisted in loss of many nerve cells, abnormalities of nuclear chromatin in the persisting pyramidal neurons and degeneration of postsynaptic dendrites. The glial changes were represented by electron-lucency of astrocytic cytoplasm and their processes. The mechanism of this reaction is unclear and the suggestion, that electron-lucent astrocytes represent a form of transformed glia especially sensitive to amino acids, releasing from degenerating neurons is discussed.

Isolation and structure of a C-terminally amidated nonopioid peptide, amidorphin-(8-26), from bovine striatum: a major product of proenkephalin in brain but not in adrenal medulla.

We have isolated and sequenced a C-terminally amidated peptide from bovine striatum. The peptide was purified to homogeneity by adsorption to XAD-2 resins and four different HPLC steps. Amino acid composition analysis and gas-phase sequence analysis revealed identity of this peptide with residues 8-26 of the proenkephalin-derived opioid peptide amidorphin, which we have recently isolated from bovine adrenal medulla. C-terminal amidation of amidorphin-(8-26) from bovine striatum was demonstrated by its stability to carboxypeptidase A digestion and full crossreactivity in a radioimmunoassay that required the C-terminal amide group as part of the recognition site. The nonopioid peptide amidorphin-(8-26), which lacks the N-terminal [Met]enkephalin sequence of amidorphin, is a major product of the opioid peptide precursor proenkephalin in the brain. In the adrenal medulla, however, where amidorphin occurs in remarkably high concentrations, amidorphin-(8-26) could not be detected. This is indicative of differential post-translational processing of proenkephalin in different tissues. In the brain, as opposed to the adrenal medulla, amidorphin is further processed at the typical cleavage signals of two basic residues, giving rise to the nonopioid peptide amidorphin-(8-26) and, possibly, to the opioid peptide [Met]enkephalin. Thus, proenkephalin in the brain might be considered as a precursor in which an opioid peptide is linked with a nonopioid peptide of possibly different biological function.

The histological changes in some organs of the laboratory mice after intragastrically given bromfenvinphos and mixture of bromfenvinphos with methoxychlor.

Bromfenvinphos (0.0-diethyl-0-1-(2.4-dichlorphenyl)-2-bromvinyl phosphate), BrV, 12.33 mg/kg/day, alone and in combination with methoxychlor ( (1,1,1-trichlor-2.2-)4-methoxyphenyl ethane), MeOCl, 24.66 mg/kg/day, were administered to laboratory mice in the olive-oil suspension through the stomach gauge once a day for 6 weeks. The histological changes developed in liver and kidneys of mice were investigated. BrV and BrV + MeOCl caused the hyperemia and fine-grained inflammatory infiltration in liver tissue. The small histological changes were observed in kidneys of animals which received the pesticides: the stellate shape lumen of the proximal convoluted kidney tubules and the vacuolar degeneration changes in the wall cells of these tubules. There occurred degeneration changes in the wall cells of these tubules. No pathological changes appeared in stomach, small and large intestine, heart, spleen and in gonads of the experimental mice.

Influence of bromfenvinfos alone and in mixture with methoxychlor on the blood indices of laboratory mice.

Bromfenvinfos (O,O-diethyl-O-1-(2,4-dichlorphenyl)-2-bromvinyl phosphate, BrV, 12.23 mg/kg/day) alone and in combination with methoxychlor (1,1,1-trichlor-2,2-(4-methoxyphenyl) ethane, MeOCl, 24.66 mg/kg/day) were administered per os daily for 6 weeks to male and female laboratory mice in the olive-oil suspension. Total leukocyte and erythrocyte count, hemoglobin level, the percentage of leukocytes and the plasma proteins were determined. BrV and BrV + MeOCl depressed the blood hemoglobin level; BrV and BrV + MeOCl treatment reduced also the erythrocyte diameter.